Tightly tie your pork shoulder.
Mix together all of the dried seasonings.
Make a bed of onions in the bottom of a large bowl. Rub the pork shoulder with the dry rub, minced garlic cloves, parsley, and olive oil. Cover and marinate overnight in the refrigerator
Let rest at room temperature for 2 hours before roasting. Preheat your oven to 450 degrees. Place the pork shoulder on a rack on a roasting pan. Save the onions and any other drippings from the bowl. Roast for 30 minutes.
Mix together the stock, red wine, canned tomatoes, and bay leaves with the saved bowl of onions. Pour that into the roasting pan. Cover the pan with foil and roast for another 15 minutes. Reduce the heat to 300 degrees and roast for 2 hours.
Remove the rack from the roasting pan. Place the pork shoulder in the juices. Cover with the foil and roast for another 2 hours or until the internal temperature reaches 180 degrees with a meat thermometer.
Let the pork rest for 30 minutes before slicing. Save the reserved juices in the roasting pan.
Remove the twine. Thinly slice the pork shoulder.
Place the pork back in the pan of juices.